Influence of Urban Sprawl on Microclimate of Abbottabad, Pakistan

Abstract

Urban centers are expanding rapidly due to quickly-increasing population which results in microclimate change due to lack of urban planning. Factors like degradation of green areas, trees, and vegetation are defining a new regime of urban environment giving rise to a lack of drinking water and lowering water tables. Consequently, unplanned urban sprawl with all its varied facets is having adverse impacts on the environment. Rapid variations in some of its climatic factors in the immediate vicinity are alarming and need to redress at war footings. This paper is an endeavor to present a hypothesis that urban sprawl plays a vital role in impacting and the influencing the microclimate of the city or the area. In this research, geospatial approaches were adopted to identify urban sprawl. Rise in land surface temperature (LST) for the last 25 years (from 1990 to 2016) has been highlighted using Landsat (5 TM, 7 ETM+ and 8 TIRS) satellite images. Weather data collected from Meteorological Department is used to identify temperature rising trends. Result of the research clearly indicates that rapid urban sprawl has adverse impacts on microclimate by increasing LST. Built-up area has been changed from 178 to 477 sq. km within the years of 1990 to 2016. Vegetated area has decreased from 770 to 602 sq. km. Water areas have been decreased from 524 to 360 sq. km within the span of last 26 years. The bare land has increased from 494 sq. km to 742 sq. km. LST in winters has risen from 17 °C to 23 °C and at times shot up to 31 °C, which is alarming. Annual mean air temperature increased by 3 °C to 4 °C from the 1980s to 2016. During summers, the average air temperature rose to a startling 33 °C from 28 °C and LST has had a steady rise from 28.4 °C to 35 °C. The alarming urban sprawl in relation to temperature rise warrants measures which are required to plan the urban planning, forestation, and ecological measures to mitigate the disastrous trends which may result in flash floods, landslides, soil erosion and sediment transport endangering downstream reservoirs, water quality and depletion in ground water table in the valley.

Monitoring war‐generated environmental security using remote sensing: A review

“…Pakistan, part of the Greater Middle East Region, also has had conflicted periods. Many people migrated after several military operations in part of the Country, causing overpopulation (Waseem et al, 2021), leading to urban sprawl and change in the microclimate. This has been investigated using LANDSAT‐5, ‐7, and ‐8 LST data, several indices, and land use classification.…”

Socio-Cultural Consequences of Urban Sprawl: A Case Study of Dera Ismail Khan (Pakistan)

“…Suburbs attract people because these areas have fresh air, abundant underground clean water, and cheaper land than the core urban areas. Instead of making a good impact, these migrations, such as leapfrogging developments, result in urban sprawl (Waseem et al, 2021). Traffic congestion and air pollution occur due to urban sprawl.…”

Urban sprawl and microclimate in the Ga East municipality of Ghana

“…The linkage between urban sprawl and climate change/variability has gained global attention in recent decades due to high rise in urban population ( Saghir and Santoro, 2018 ; Feng and Gauthier, 2021 ; Ewing and Hamidi, 2015 ), high occurrence rates of cataclysmic floods, torrential rainfall, extreme heat waves and exposure ( Frimpong et al., 2017 ; Nunfam et al., 2021 ), elevated wildlife extinction, rising sea or ocean levels and increases in energy consumption ( Waseem et al., 2021 ; IPCC, 2014 ; Battista and de Lieto Vollaro, 2017 ). Rainfall and temperature variations are seen to be connected to changes in LULC ( Fu and Weng, 2016 ; Cao et al., 2015 ).…”

“…These changes in climate are largely human induced ( Yao et al., 2015 ; Rosenzweig, 2007 ; Sachs, 2008 ); for instance, over the few years urban sprawl has resulted in conversion of vegetation and grassland into built-up areas ( Langemeyer et al., 2021 ; Afriyie et al., 2019 ; Berthal et al., 2019 ; Abass et al., 2018 ) and increased fuel consumption from both electricity production and transport ( Feng and Gauthier, 2021 ), with the overall effect being increased carbon dioxide emissions ( Asante and Amuakwa-Mensah, 2015 ; Saboori et al., 2014 ). In studying the relationship between sprawl and climate change, the use of Geo-spatial techniques are relevant as they give precise and accurate changes in the various land uses ( Waseem et al., 2021 ), as well as lessening climatic risks and trepidations in the fast urban development process ( Wang et al. , 2015 ) .…”